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The mission of the CEOS Land Product Validation (LPV) subgroup is to coordinate the quantitative validation of satellite-derived products. The focus lies on standardized intercomparison and validation across products from different satellite, algorithms, and agency sources.

The sub-group consists of 11 Focus Areas, with 2 co-leads responsible for each land surface variable (essential climate and biodiversity variables).

CEOS VALIDATION HIERARCHY

Validation Stage - Definition and Current State

Variable

0

No validation.
Product accuracy has not been assessed. Product considered beta.

1

Product accuracy is assessed from a small (typically < 30) set of locations and time periods by comparison with in-situ or other suitable reference data.

Snow
Fire Radiative Power

2

Product accuracy is estimated over a significant set of locations and time periods by comparison with reference in situ or other suitable reference data. Spatial and temporal consistency of the product and consistency with similar products has been evaluated over globally representative locations and time periods. Results are published in the peer-reviewed literature.

fAPAR
Phenology
Burned Area
Land Cover
LAI

3

Uncertainties in the product and its associated structure are well quantified from comparison with reference in situ or other suitable reference data. Uncertainties are characterized in a statistically rigorous way over multiple locations and time periods representing global conditions. Spatial and temporal consistency of the product and with similar products has been evaluated over globally representative locations and periods. Results are published in the peer-reviewed literature.

Vegetation Indicies
Albedo
Soil Moisture
LST & EmissiSvity
Phenology

4

Validation results for stage 3 are systematically updated when new product versions are released and as the time-series expands.

Active Fire

VALIDATION FRAMEWORK

To reach validation stage 4, LPV has developed a framework for product intercomparison and validation. This framework is based on a citable protocol, fiducial reference data, and automated subsetting. Ideally, each of these parts will be integrated into an online platform where quantitative tests are run, and standardized intercomparison and validation results reported for all products used in the validation exercise. The goal is to implement this framework for each product variable. Information on variable-specific status of the implementation is available through the focus area pages.

LPV is currently in the process of selecting supersites with fully characterized land surface and vegetation cover for the parameterization of 3D radiative transfer models. These sites will serve as testbeds for in situ sampling strategies and product algorithm intercomparison.

Outreach activities of LPV include distribution of validation news through focus area email lists (see subscription menu in the left panel of this page) and regularly organized validation sessions at conferences, such as AGU and EGU (see announcements panel at top left).

LPV follows international terminology standards for the evaluation of measurement data